[PATCH v4 07/10] irqchip / GICv3 / ACPI: Add GICR support via GICC structures

Marc Zyngier marc.zyngier at arm.com
Thu Aug 6 09:42:50 PDT 2015


On 05/08/15 15:11, Hanjun Guo wrote:
> On 08/04/2015 09:37 PM, Marc Zyngier wrote:
>> On 29/07/15 11:08, Hanjun Guo wrote:
>>> On systems supporting GICv3 and above, in MADT GICC structures, the
>>> field of GICR Base Address holds the 64-bit physical address of the
>>> associated Redistributor if the GIC Redistributors are not in the
>>> always-on power domain, so instead of init GICR regions via GIC
>>> redistributor structure(s), init it with GICR base address in GICC
>>> structures in that case.
>>>
>>> As GICR base in MADT GICC is another way to indicate the GIC version
>>> is 3 or 4, add its support to find out the GIC versions.
>>>
>>> Signed-off-by: Hanjun Guo <hanjun.guo at linaro.org>
>>> ---
>>>   drivers/irqchip/irq-gic-acpi.c       |  35 ++++++-
>>>   drivers/irqchip/irq-gic-v3.c         | 197 +++++++++++++++++++++++++++++++----
>>>   include/linux/irqchip/arm-gic-acpi.h |   2 +
>>>   3 files changed, 215 insertions(+), 19 deletions(-)
>>>
>>> diff --git a/drivers/irqchip/irq-gic-acpi.c b/drivers/irqchip/irq-gic-acpi.c
>>> index 95454e3..3e5c8f4 100644
>>> --- a/drivers/irqchip/irq-gic-acpi.c
>>> +++ b/drivers/irqchip/irq-gic-acpi.c
>>> @@ -21,6 +21,11 @@ static u8 gic_version __initdata = ACPI_MADT_GIC_VERSION_NONE;
>>>
>>>   static phys_addr_t dist_phy_base __initdata;
>>>
>>> +u8 __init acpi_gic_version(void)
>>> +{
>>> +       return gic_version;
>>> +}
>>> +
>>>   static int __init
>>>   acpi_gic_parse_distributor(struct acpi_subtable_header *header,
>>>                             const unsigned long end)
>>> @@ -38,6 +43,27 @@ acpi_gic_parse_distributor(struct acpi_subtable_header *header,
>>>   }
>>>
>>>   static int __init
>>> +gic_acpi_parse_madt_gicc(struct acpi_subtable_header *header,
>>> +                        const unsigned long end)
>>> +{
>>> +       struct acpi_madt_generic_interrupt *gicc;
>>> +
>>> +       gicc = (struct acpi_madt_generic_interrupt *)header;
>>> +
>>> +       if (BAD_MADT_GICC_ENTRY(gicc, end))
>>> +               return -EINVAL;
>>> +
>>> +       /*
>>> +        * If GICC is enabled but has no valid gicr base address, then it
>>> +        * means GICR base is not presented via GICC
>>> +        */
>>> +       if ((gicc->flags & ACPI_MADT_ENABLED) && !gicc->gicr_base_address)
>>> +               return -ENODEV;
>>> +
>>> +       return 0;
>>> +}
>>> +
>>> +static int __init
>>>   match_gic_redist(struct acpi_subtable_header *header, const unsigned long end)
>>>   {
>>>          return 0;
>>> @@ -51,7 +77,14 @@ static bool __init acpi_gic_redist_is_present(void)
>>>          count  =  acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR,
>>>                                          match_gic_redist, 0);
>>>
>>> -       /* that's true if we have at least one GIC redistributor entry */
>>> +       /* has at least one GIC redistributor entry */
>>> +       if (count > 0)
>>> +               return true;
>>> +
>>> +       /* else try to find GICR base in GICC entries */
>>> +       count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT,
>>> +                                     gic_acpi_parse_madt_gicc, 0);
>>> +
>>>          return count > 0;
>>>   }
>>>
>>> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
>>> index ebc5604..b72ccbb 100644
>>> --- a/drivers/irqchip/irq-gic-v3.c
>>> +++ b/drivers/irqchip/irq-gic-v3.c
>>> @@ -389,9 +389,8 @@ static void __init gic_dist_init(void)
>>>                  writeq_relaxed(affinity, base + GICD_IROUTER + i * 8);
>>>   }
>>>
>>> -static int gic_populate_rdist(void)
>>> +static int gic_populate_rdist_with_regions(u64 mpidr)
>>>   {
>>> -       u64 mpidr = cpu_logical_map(smp_processor_id());
>>>          u64 typer;
>>>          u32 aff;
>>>          int i;
>>> @@ -439,6 +438,34 @@ static int gic_populate_rdist(void)
>>>                  } while (!(typer & GICR_TYPER_LAST));
>>>          }
>>>
>>> +       return -ENODEV;
>>> +}
>>> +
>>> +#ifdef CONFIG_ACPI
>>> +/*
>>> + * Populate redist when GIC redistributor address is presented in ACPI
>>> + * MADT GICC entries
>>> + */
>>> +static int gic_populate_rdist_with_gicr_base(u64 mpidr);
>>> +#else
>>> +static inline int gic_populate_rdist_with_gicr_base(u64 mpidr)
>>> +{
>>> +       return -ENODEV;
>>> +}
>>> +#endif
>>> +
>>> +static int gic_populate_rdist(void)
>>> +{
>>> +       u64 mpidr = cpu_logical_map(smp_processor_id());
>>> +
>>> +       if (gic_data.nr_redist_regions) {
>>> +               if (!gic_populate_rdist_with_regions(mpidr))
>>> +                       return 0;
>>> +       } else {
>>> +               if (!gic_populate_rdist_with_gicr_base(mpidr))
>>> +                       return 0;
>>> +       }
>>> +
>>>          /* We couldn't even deal with ourselves... */
>>>          WARN(true, "CPU%d: mpidr %llx has no re-distributor!\n",
>>>               smp_processor_id(), (unsigned long long)mpidr);
>>> @@ -900,6 +927,16 @@ IRQCHIP_DECLARE(gic_v3, "arm,gic-v3", gic_of_init);
>>>   #endif
>>>
>>>   #ifdef CONFIG_ACPI
>>> +
>>> +struct acpi_gicc_redist {
>>> +       struct list_head list;
>>> +       u64 mpidr;
>>> +       phys_addr_t phys_base;
>>> +       void __iomem *redist_base;
>>> +};
>>> +
>>> +static LIST_HEAD(redist_list);
>>> +
>>>   static struct redist_region *redist_regs __initdata;
>>>   static u32 nr_redist_regions __initdata;
>>>   static phys_addr_t dist_phys_base __initdata;
>>> @@ -932,6 +969,17 @@ gic_acpi_register_redist(u64 phys_base, u64 size)
>>>          return 0;
>>>   }
>>>
>>> +static void __init
>>> +gic_acpi_release_redist_regions(void)
>>> +{
>>> +       int i;
>>> +
>>> +       for (i = 0; i < nr_redist_regions; i++)
>>> +               if (redist_regs[i].redist_base)
>>> +                       iounmap(redist_regs[i].redist_base);
>>> +       kfree(redist_regs);
>>> +}
>>> +
>>>   static int __init
>>>   gic_acpi_parse_madt_redist(struct acpi_subtable_header *header,
>>>                          const unsigned long end)
>>> @@ -989,9 +1037,130 @@ static int gic_acpi_gsi_desc_populate(struct acpi_gsi_descriptor *data,
>>>   }
>>>
>>>   static int __init
>>> +gic_acpi_add_gicc_redist(phys_addr_t phys_base, u64 mpidr)
>>> +{
>>> +       struct acpi_gicc_redist *redist;
>>> +
>>> +       redist = kzalloc(sizeof(*redist), GFP_KERNEL);
>>> +       if (!redist)
>>> +               return -ENOMEM;
>>> +
>>> +       redist->mpidr = mpidr;
>>> +       redist->phys_base = phys_base;
>>> +
>>> +       if (acpi_gic_version() == ACPI_MADT_GIC_VERSION_V3)
>>> +               /* RD_base + SGI_base */
>>> +               redist->redist_base = ioremap(phys_base, 2 * SZ_64K);
>>> +       else
>>> +               /*
>>> +                * RD_base + SGI_base + VLPI_base,
>>> +                * we don't map reserved page as it's buggy to access it
>>> +                */
>>> +               redist->redist_base = ioremap(phys_base, 3 * SZ_64K);
>>> +
>>> +       if (!redist->redist_base) {
>>> +               kfree(redist);
>>> +               return -ENOMEM;
>>> +       }
>>> +
>>> +       list_add(&redist->list, &redist_list);
>>> +       return 0;
>>> +}
>>> +
>>> +static void __init
>>> +gic_acpi_release_gicc_redist(void)
>>> +{
>>> +       struct acpi_gicc_redist *redist, *t;
>>> +
>>> +       list_for_each_entry_safe(redist, t, &redist_list, list) {
>>> +               list_del(&redist->list);
>>> +               iounmap(redist->redist_base);
>>> +               kfree(redist);
>>> +       }
>>> +}
>>> +
>>> +static int __init
>>> +gic_acpi_parse_madt_gicc(struct acpi_subtable_header *header,
>>> +                        const unsigned long end)
>>> +{
>>> +       struct acpi_madt_generic_interrupt *gicc;
>>> +
>>> +       gicc = (struct acpi_madt_generic_interrupt *)header;
>>> +
>>> +       if (BAD_MADT_GICC_ENTRY(gicc, end))
>>> +               return -EINVAL;
>>> +
>>> +       /*
>>> +        * just quietly ingore the disabled CPU(s) and continue
>>> +        * to find the enabled one(s), if we return error here,
>>> +        * the scanning will be stopped.
>>> +        */
>>> +       if (!(gicc->flags & ACPI_MADT_ENABLED))
>>> +               return 0;
>>> +
>>> +       return gic_acpi_add_gicc_redist(gicc->gicr_base_address,
>>> +                                       gicc->arm_mpidr);
>>> +}
>>> +
>>> +static int gic_populate_rdist_with_gicr_base(u64 mpidr)
>>> +{
>>> +       struct acpi_gicc_redist *redist;
>>> +       void __iomem *ptr;
>>> +       u32 reg;
>>> +
>>> +       list_for_each_entry(redist, &redist_list, list) {
>>> +               if (redist->mpidr != mpidr)
>>> +                       continue;
>>> +
>>> +               ptr = redist->redist_base;
>>> +               reg = readl_relaxed(ptr + GICR_PIDR2) & GIC_PIDR2_ARCH_MASK;
>>> +               if (reg != GIC_PIDR2_ARCH_GICv3 && reg != GIC_PIDR2_ARCH_GICv4) {
>>> +                       pr_warn("No redistributor present @%p\n", ptr);
>>> +                       return -ENODEV;
>>> +               }
>>> +
>>> +               gic_data_rdist_rd_base() = ptr;
>>> +               gic_data_rdist()->phys_base = redist->phys_base;
>>> +               pr_info("CPU%d: found redistributor %llx phys base:%pa\n",
>>> +                       smp_processor_id(),
>>> +                       (unsigned long long)mpidr,
>>> +                       &gic_data_rdist()->phys_base);
>>> +               return 0;
>>> +       }
>>> +
>>> +       return -ENODEV;
>>> +}
>>> +
>>> +static int __init collect_gicr_base(struct acpi_table_header *table)
>>> +{
>>> +       int count;
>>> +
>>> +       /* Collect redistributor base addresses in GICR entries */
>>> +       count = acpi_parse_entries(ACPI_SIG_MADT,
>>> +                       sizeof(struct acpi_table_madt),
>>> +                       gic_acpi_parse_madt_redist, table,
>>> +                       ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR, 0);
>>> +       if (count > 0)
>>> +               return 0;
>>> +
>>> +       pr_info("No valid GICR entries exist, try GICC entries\n");
>>> +
>>> +       /* Collect redistributor base addresses in GICC entries */
>>> +       count = acpi_parse_entries(ACPI_SIG_MADT,
>>> +                       sizeof(struct acpi_table_madt),
>>> +                       gic_acpi_parse_madt_gicc, table,
>>> +                       ACPI_MADT_TYPE_GENERIC_INTERRUPT, 0);
>>> +       if (count > 0 && !list_empty(&redist_list))
>>> +               return 0;
>>> +
>>> +       pr_info("No valid GICC entries exist for GICR base\n");
>>> +       return -ENODEV;
>>> +}
>>> +
>>> +static int __init
>>>   gic_acpi_init(struct acpi_table_header *table)
>>>   {
>>> -       int count, i, err = 0;
>>> +       int count, err = 0;
>>>          void __iomem *dist_base;
>>>
>>>          /* Get distributor base address */
>>> @@ -1020,30 +1189,22 @@ gic_acpi_init(struct acpi_table_header *table)
>>>          }
>>>
>>>          /* Collect redistributor base addresses */
>>> -       count = acpi_parse_entries(ACPI_SIG_MADT,
>>> -                       sizeof(struct acpi_table_madt),
>>> -                       gic_acpi_parse_madt_redist, table,
>>> -                       ACPI_MADT_TYPE_GENERIC_REDISTRIBUTOR, 0);
>>> -       if (count <= 0) {
>>> -               pr_info("No valid GICR entries exist\n");
>>> -               err = -EINVAL;
>>> -               goto out_redist_unmap;
>>> -       }
>>> +       if (collect_gicr_base(table))
>>> +               goto out_release_redist;
>>>
>>>          err = gic_init_bases(dist_base, redist_regs, nr_redist_regions, 0,
>>>                               (void *)ACPI_IRQ_MODEL_GIC);
>>>          if (err)
>>> -               goto out_redist_unmap;
>>> +               goto out_release_redist;
>>>
>>>          acpi_set_irq_model(ACPI_IRQ_MODEL_GIC, ACPI_IRQ_MODEL_GIC,
>>>                             gic_acpi_gsi_desc_populate);
>>>          return 0;
>>>
>>> -out_redist_unmap:
>>> -       for (i = 0; i < nr_redist_regions; i++)
>>> -               if (redist_regs[i].redist_base)
>>> -                       iounmap(redist_regs[i].redist_base);
>>> -       kfree(redist_regs);
>>> +out_release_redist:
>>> +       gic_acpi_release_redist_regions();
>>> +       if (!list_empty(&redist_list))
>>> +               gic_acpi_release_gicc_redist();
>>>   out_dist_unmap:
>>>          iounmap(dist_base);
>>>          return err;
>>> diff --git a/include/linux/irqchip/arm-gic-acpi.h b/include/linux/irqchip/arm-gic-acpi.h
>>> index 56cd82c..0d43f515 100644
>>> --- a/include/linux/irqchip/arm-gic-acpi.h
>>> +++ b/include/linux/irqchip/arm-gic-acpi.h
>>> @@ -21,5 +21,7 @@
>>>   #define ACPI_GIC_CPU_IF_MEM_SIZE       (SZ_8K)
>>>   #define ACPI_GICV3_DIST_MEM_SIZE       (SZ_64K)
>>>
>>> +u8 acpi_gic_version(void);
>>> +
>>>   #endif /* CONFIG_ACPI */
>>>   #endif /* ARM_GIC_ACPI_H_ */
>>> --
>>> 1.9.1
>>>
>>
>> This looks absolutely horrid. Why don't you simply populate one region
>> per redistributor, add a flag to struct redist_region so we know not to
>> check for GICR_TYPER_LAST but to move on to the next region instead?
> 
> There is no regions in GICC structures, and only have the GICR base
> address for each CPU, I think we can't figure out which GICR bases
> are belonging to a GICR region.
> 
> So do you mean populate each GICR base as a region, and use the
> existing infrastructure ?

This is exactly what I wrote.

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...



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